A Comparative Study on the Performance of Fiber-Based Biosorbents in the Purification of Biodiesel Derived from Camelina sativa
Pages 123-132

Jie Yang, Quan (Sophia) He, Haibo Niu, Kenneth Corscadden and Claude Caldwell

DOI: http://dx.doi.org/10.6000/1929-6002.2016.05.04.2

Published: 02 January 2017

Abstract: Biodiesel has received great interest as a promising substitute for petrodiesel. Biodiesel purification which follows the transesterification process is typically carried out using a wet washing process that generates large amounts of wastewater. Consequently, alternative methods are emerging as sustainable options for biodiesel purification. One of such methods is a dry washing process. In this paper, the performance of three dry washing media (commercially available BD-Zorb, sawdust and wood shavings) were evaluated as potentially suitable options for the purification of biodiesel derived from Camelina sativa. The results indicate that for the crude camelina biodiesel with an initial soap content of 9007 ppm, BD-Zorb exhibited the best purification performance. The soap removal capacity of BD-Zorb, sawdust, and wood shavings was 51.1 mL/g, 24.4 mL/g, and 9.4 mL/g respectively. The primary mechanism of soap removal using sawdust and wood shavings media was physical filtration and adsorption. While for adsorbent BD-Zorb, soap removal mechanism included adsorption and ion exchange due to the existence of a small amount of resins. The ion exchange led to a high acid number (1 mg KOH/g) of the purified biodiesel, and failed to meet the ASTM D6751 specifications (<0.5 mg KOH/g).

A Novel Approach to Synthesize Helix Wave Hollow Fiber Membranes for Separation Applications
Pages 8-14
Sung Ryul Park, Jeong-Hoon Kim, Aamer Ali, Francesca Macedonio and Enrico Drioli

DOI: http://dx.doi.org/10.6000/1929-6037.2015.04.01.2

Published: 13 March 2015

Abstract: Helix wave hollow fiber membranes are promising candidate to mitigate fouling and polarization effects in membrane operations. Current study describes a novel but simple approach to synthesize hollow fiber membranes with helix wave configuration. Poly(ether sulfone) (PES) based helix-waved hollow fiber membranes have been fabricated by dry-wet phase inversion process by using asymmetric coagulation conditions. Frequencies of the wave cycle have been observed approximately 20 and the wave length 7.1-7.6mm under the specifically required operating conditions defined by dope solution extrudate rate of 1g/min through 4cm of air-gap heights with 8.6m/min of winding speeds. On the other hand, simple hollow fibers are formed when the elongation force exerted by the winder is much higher than the surface tension of the external coagulant. The process can be useful for making polymer fibers for other applications as well.

A Comparison between Several Commercial Polymer Hollow Fiber Membranes for Gas Separation
Pages 1-15

Xiao Yuan Chen, Serge Kaliaguine and Denis Rodrigue

DOI: http://dx.doi.org/10.6000/1929-6037.2017.06.01.1

Published: 07 April 2017

Abstract: Polyethersulfone (PES), polyetherimide (Ultem^® 1000), and polyimide (Matrimid^® 5218) are common commercial polymers used to produce hollow fiber membranes for different gas separation applications. In this work, asymmetric hollow fiber membranes were prepared using these polymers by a phase inversion technique. The effects of spinning parameters (composition of the dope and bore solution, bore flow rate, air gap distance, temperature of the spinneret and coagulation bath, as well as take-up speed) on the membrane structure and gas permeation properties were investigated. The membrane separation performances were characterized by measuring their gas permeation properties (permeance and selectivity) for different gases (H₂, CO₂, O₂, N₂, and CH₄) and by their cross-sectional morphology using scanning electron microscopy (SEM). The relationships between the gas separation performance of the hollow fibers and the intrinsic gas properties of the dense flat membranes made of the same materials were also studied. A comparison between the average apparent skin layer thickness calculated from O₂ permeability/permeance, and the results based on SEM images was made and good agreement was obtained between both results.

A Pilot-Plant Test of a Membrane Bioreactor with a Novel Membrane Made from Chlorinated Poly (Vinyl Chloride) (CPVC) and Hydroxy-Propyl Cellulose
Pages 74-88
Junsuke Morita, Norifumi Shimada, Masao Higashi and Tooru Kitagawa

DOI: http://dx.doi.org/10.6000/1929-6037.2015.04.02.5

Published: 08 June 2015

Abstract: A pilot-plant test that can treat an amount of 30 ton per day of wastewater is performed. The purpose of this test is to prove the usefulness and applicability of newly developed microfiltration membranes made from chlorinated poly (vinyl chloride) and polyester nonwoven. Here, the hydrophilicity of membranes is important and hydroxyl-propyl cellulose is used to mitigate their hydrophobicity. The membrane consists of the novel structure in which small particles made from hydroxyl-propyl cellulose gel are homogeneously dispersed and attached on the surface of micro fibrils in the structure. The result of the pilot-plant test shows that the newly developed membrane has anti-fouling properties better than that of a conventional membrane made from chlorinated poly (vinyl chloride) by another company. It still shows high hydrophilicity after the use of one year, while the conventional one loses such properties. Saving electricity in producing water is one of important issues in developing membrane bioreactor systems and the case in use of newly-developed membranes is revealed to need 2.0 kWh of electricity to produce 1 m³ of filtered water. This amount is fairly good and reasonable when the pilot-plant test is considered to belong to a medium-size facility.

Keywords: MBR, chlorinated poly(vinyl chloride), hydroxy-propyl cellulose, fouling, hydrophilicity.